This proposed project is a continuation of "English and Spanish Assessment of Cognition in Elderly" (R01AG10220), a grant project with a primary purpose of developing a neuropsychological test battery with matched English and Spanish language versions. In the initial funding cycle a community based sample of English and Spanish speaking elderly was recruited for participation in the neuropsychological test development process using a door to door community survey. Information regarding cognitive functioning, independent functioning and physical performance capacity was obtained on 760 subjects including 372 Hispanic elderly. Neuropsychological test administration was completed with 208 English speaking and 200 Spanish speaking elderly 60 years of age and older. A 12 scale neuropsychological test battery was developed using item response theory methods applied to this subject sample. The proposed continuation of this project will be for four years. A primary goal of this continuation will be to comprehensively evaluate the reliability, validity and clinical utility of these tests. An additional goal will be to refine the measurement characteristics of these tests based upon a larger sample ad to extend measurement to lower levels of functioning. A new sample of 400 English speaking and 400 Spanish speaking participants will be recruited, in addition to 50 English speaking and 50 Spanish speaking dementia patients and 40 English speaking and 30 Spanish unilateral stroke patients (half left and half right hemisphere stroke). Specific aims will be as follows: 1) validate the neuropsychological test being developed by identifying English and Spanish speaking subjects with cognitive impairment and comparing them with English and Spanish speaking subject who are non-impaired, 2) test the concurrent validity of the neuropsychological tests being developed in comparison with currently available clinical neuropsychological tests, 3) expand the neuropsychological test battery by incorporating tests from other important neuropsychological domains 4) evaluate the validity of the expanded neuropsychological test battery for measuring neuropsychological deficits associated with unilateral strokes 5) collect normative data for English and Spanish speaking elderly, and 6) utilize the increase sample size to improve estimation of item parameters and to improve measurement capacity at low ability levels associated with dementia.